Hoechst Aktiengesellschaft

Manfred Wolter

Gero Heymer

Friedrich-Wilhelm Dorn

Joachim Kandler

Hans-Werner Stephan

The invention relates to improving the degree of graphitization of carbon black produced by subjecting hydrocarbons which are liquid or gaseous under normal conditions to a thermal conversion reaction in the presence of oxygen or an oxygen-containing gas and steam, if desired, at temperatures of 1200.degree. to 2000.degree. C. and pressures of 1 to 80 bars. To this end, the carbon black is conveyed downwardly in a quasi-fluid state, within 1 to 5 hours through a sojourn zone in upright position, the sojourn zone being maintained at a temperature of at least 1200.degree. C. The invention relates to an apparatus for carrying out this process, the apparatus comprising a graphite tube; a steel container concentrically surrounding the graphite tube; a feed pipe penetrating into the interior of the graphite tube; a water-cooled discharge means; and a nitrogen feed inlet arranged below the lower end of the graphite tube; the space left between the graphite tube and steel container being occupied by insulating material.

Apparatus for improving the degree of graphitization of carbon black,

The disclosure relates to a process for the discontinuous separation of a solid consisting predominantly of carbon black from its aqueous suspension by filtration. To this end, the disclosure provides for use to be made of a tube pressure filter which is operated under a final pressure of 30 to 100 bars.

Process for separating carbon black from an aqueous suspension

The invention relates to a process for removing carbon black from an aqueous suspension obtained by washing a gas containing carbon black with water. To this end, a gas stream comprising hydrocarbons and at least one inert gas is introduced into a suspension having a solids content of from 0.5 to 4% by weight, at a temperature of from 10.degree. to 80.degree. C. In so doing, the carbon black agglomerates and collects on the surface of the suspension water from which it is separated, for example by skimming it off. The gas stream is produced by passing inert gas over the separated carbon black containing the hydrocarbons and heated to 200.degree. to 400.degree. C., the carbon black being converted into a dry, free-flowing material.

Process for removing carbon black from aqueous suspensions

The invention relates to a process for the removal of metals, especially of iron and/or nickel and/or vanadium or their compounds, from carbon black. To this end, the invention provides for an aqueous carbon black suspension to be heated to a temperature of about 30.degree. to 90.degree. C., for chlorine to be passed therethrough with agitation. The chlorine gas is used in a stoichiometric excess, based on the metal content of the aqueous carbon black suspension. Next, the carbon black is separated from the aqueous suspension and dried.

Growing community of inventors

Hurth, Germany

Manfred Wolter